A thin film, solid-state battery is typically comprised of a multilayer structure that includes solid electrodes and a solid electrolyte. By utilizing a thin film architecture, the size of the battery can be substantially reduced compared to conventional rechargeable batteries, resulting in a lighter, more flexible battery with a higher energy density, higher power density, and a longer lifetime. For example, thin film lithium-ion batteries have been developed using lithium-oxide complexes, such as LiCoO2, as cathodes and lithium-ion conducting electrolytes, such as lithium phosphorous oxynitride (LiPON). Such batteries are readily used in portable electronic devices such as smart phones, tablets, and laptops.
However, conventional thin film, solid-state batteries exhibit dimensional and processing limitations that inhibit further performance improvements. For example, thin film lithium-ion batteries require film thicknesses of at least 10 μm for operation. A thin film battery can also include a separator, in addition to the cathode, anode, and solid electrolyte, as well as other electronics components, e.g., capacitors, to augment the performance, particularly for high power applications. Based on the constraints imposed on the thickness of each constituent layer and the numerous materials used, the miniaturization of conventional thin film batteries is limited to tens of microns. The size limitation fundamentally limits the performance of the battery technology and limits the manner in which thin film batteries are integrated with electronic devices. For example, conventional thin film batteries are typically standalone components with interconnects that couple the battery to the device. Furthermore, the manufacture of thin film lithium-ion batteries can require numerous steps, including annealing processes at high temperatures, which increase manufacturing complexity and cost and further limits the ability to integrate batteries with electronic devices, e.g., an integrated circuit (IC).